MS SQL column encryption without certificate - sql

Question

I am trying to encrypt one of my sensitive columns in a SQL Server table.
I tried AES256 encryption with this script, and it works perfect.
But I don't want to create Certificates, or Symmetric Keys on my SQL Server as it may be a security problem later.
How can I encrypt the data with a single password or key in my query ?
Another problem with this method is, I can use only a single master password for
my encryption.
CREATE MASTER KEY ENCRYPTION
BY PASSWORD = '$Passw0rd'
GO
CREATE CERTIFICATE AESEncryptTestCert
WITH SUBJECT = 'AESEncrypt'
GO
CREATE SYMMETRIC KEY AESEncrypt
WITH ALGORITHM = AES_256 ENCRYPTION -- TRIPLE_DES ENCRYPTION
BY CERTIFICATE AESEncryptTestCert;
OPEN SYMMETRIC KEY AESEncrypt DECRYPTION
BY CERTIFICATE AESEncryptTestCert
SELECT ENCRYPTBYKEY(KEY_GUID('AESEncrypt'),'The text to be encrypted');

Answer 1

You can use EncryptByPassPhrase and DecryptByPassPhrase, for example:
DECLARE #CypherText varbinary(8000)
DECLARE #ClearText varchar(128) = 'Text to encrypt'
SET #CypherText = EncryptByPassPhrase ('MyP#ssword123', #ClearText)
DECLARE #DecryptedText varchar(128)
SET #DecryptedText = DecryptByPassPhrase('MyP#ssword123', #CypherText)
SELECT #CypherText AS CypherText, #DecryptedText As DecryptedText
EDIT:
The above code produces the following output
+----------------------------------------------------------------------------+-----------------+
| CypherText | DecryptedText |
+----------------------------------------------------------------------------+-----------------+
| 0x01000000F1D813F399246484FDA8D7C7D22BFBCF748D3F6033D4E9980FCDC58A387A1A93 | Text to encrypt |
+----------------------------------------------------------------------------+-----------------+